I used to grow irises between my roses, but they didn't really appreciate all of the watering the roses needed.
Perennials didn't work for me because they got so big that they'd obscure or overwhelm the roses.
I prefer to grow annuals and some very small and slow-growing perennials in my rose beds, such as Anagallis, Catananche, Salpiglossis, Schizanthus, Nemophila, Verbena, Nigella, Malcolmia, Clarkia, Cosmos, Allysum, poppies, forget-me-nots, and small pelargoniums.
